What are the factors predicting visual field fluctuation in glaucoma patients?

Visual field (VF) fluctuation in glaucoma patients is predicted by several factors, which include Asian descent, left eye and larger intraocular pressure (IOP) among others, a study has shown.

In the global model, the predictors of VF fluctuation were intervening cataract surgery (0.090 dB; p=0.023), worse baseline mean deviation (MD; –0.145 dB; p<0.001), left eye (0.063 dB; p=0.022), longer follow-up (0.130 dB; p<0.001), Asian descent (0.265; p=0.006), faster VF decay rate (–0.090 dB; p<0.001), larger IOP fluctuation (0.051 dB; p<0.001), and higher false positive (FP) rate (0.145 dB; p<0.001) and false negative (FN) rate (0.220 dB; p<0.001).

In the pointwise model, increased fluctuation correlated with the following factors: higher VF frequency (0.223 dB; p=0.002), worse baseline MD (–0.535 dB; p<0.001), larger IOP fluctuation (0.039 dB; p=0.022), intervening glaucoma surgery (0.190 dB; p=0.01), longer follow-up (0.340 dB; p<0.001), faster VF decay rate (–0.340 dB; p<0.001), and higher FP rate (0.255 dB; p<0.001) and FN rate (0.395 dB; p<0.001).

The multivariable model explained 28 percent of the global variance and 57 percent of the pointwise variance.

“In the presence of factors predictive of high fluctuation, increased frequency of testing and better analytics will help to identify VF progression more accurately,” the investigators said.

This retrospective cohort study included 1,392 eyes of 816 patients with six or more VFs and ≥3 years of follow-up. For each eye, the VF MD and the pointwise sensitivities were regressed against time to model the series trend. The root mean square error was estimated as a measure of variability.

The investigators selected potential predictors with least absolute shrinkage and selection operator regression. These included ethnicity, eye laterality, IOP fluctuation, glaucoma type, intervening cataract or glaucoma surgery, baseline best corrected-visual acuity, frequency of testing, length of follow-up, baseline MD, rates of VF progression, and median FP and FN responses.